Process of regenerating cellulose from viscose



Patented Mar. 3, 1925.

UNITED STATES PATENT or FICE.

JAMES M. LEAVER, OF OAKLAND, CALIFORNIA, ASSIGNOR TO THE PACIFIC LUMBER COMPANY, OF SAN FRANCISCO. CALIFORNIA. A CORPORATION OF MAINE.

PROCESS OF REGENERATING CELLULOSE FROM VISCOSE.

N0 Drawing. Application filed November To all whom it may concern:

Be it known that 1, James M. LrAvnn, a citizen of the United States, residing at Oakland, in the county of Alameda and State of California, have invented certain new and useful Improvements in a Process of Regencrating Cellulose. from Viscose, of which the following is a specification.

This inventiou' relates to the regeneration or precipitatioi'i of cellulose sodium xanthate, ordinarily known as viscose from its solutions as carried out in the production of strands or sheets of precipitated viscose, and particularly in the formation of filaments of viscose artificial silk.

The principal objects of my invention are intended to be realized with viscose derived from certain kinds of ligno cellulose, and are to effect a modification in the preoipitating bath in which thefilaments are precipitated, or in the viscose solution itself, by adding thereto an extract of the parent wood from which the cellulose was obtained, whereby the filaments considerably toughened and the subsequent operations in completing the filaments are made easier.

One of the certain kinds of wood contemplated as a source of the cellulose to be used with my process is what is known as red- WOOd,-S :g lt0i(t sentpcr-oiicas. This tree is very rich in extractive matter composed largely of phenols, tannins and glucosides in variable proportionsdepending on the age of the tree and its location.

Most of these extractive substances are soluble in'hot water, and the resulting extract when concentrated is susceptible of various applications in the arts of tanning and dyeing.

Furthermore, I have discovered that this extract when added to a viscose solution ready for spinning-of artificial silk threads or filaments in the well known'iuanncr, has the very desirable property of furthering the coagulation and of toughening the precipitated filaments.

Moreover I have also discovered that this.

extract when added to the usual coagulating bath as used for the precipitation of viscose filaments, produces a much superior filament as it prevents adhesion of the filaments in multiple spinning, and thereby greatly pro- 26, 1923. Serial No. 677,178.

aforesaid as they emerge from the spinning or pre ipitating bath the. slight coating they carry protects them from the oxidizing or other action of the atmosphere, and the final treatment is greatly facilitated.

In using the extract as designated the filaments are stained a brownish color which would naturally dry after final washing to a copper red hue. This is not objectionable .if the filaments are to be dyed to any of the darker shades as the tannin compounds left in the filaments will act as a mordant in pro duciug very fast colors. I

If either a light shade, or pure White filament of artificial silk is desired, the tannin or compound stain is easily discharged by subjecting the filaments to the action of a light bleaching bath, without al'l'ecting or weakening the fibers.

It is of course apparent that-the process is applicable to viscose from other woods than redwood yielding extractive matter having a toughening or tanning action 011 the precipitated viscose. ()r the use of any such extract with ligno-cellulose derived from a parent tree yielding no such suitable extract, or with cotton cellulose viscose solutions, in connection with the precipitation of filaments or sheets, and whether combined with the viscose, or with the precipitating bath, or with both, or with a subsequent bath, or with all three.

I claim 1. In the regeneration of cellulose from viscose solutions, the use in any proportions of an extract of the Sequoia.

In the regeneration of ligno-cellulose from viscose solutions, the use in any proportions of an extract of the Sequoia.

Jhlu the regeneration of ligno-eellulose froi'ii viscose prepared from wood of the Sequoia, the addition of an extract of the same kind of a tree to the viscose solution preparatory to precipitation of the cellulose.

l. In the regeneration ofligno-ccllulose from viscose prepared from wood of the Sequoia, the addition of an extract of the tree to the bath used cellulose,

for precipitating the 5. In the regenerationiof cellulose from viscose prepared from the wood of the Sequoia, the addition of an extract of the wood to the viscose solution preparatory to 6 precipitation ot the cellulose,

and to the bath used for prec pitating the cellulose.

6. In the formation from viscose by precipitation,

of strands or sheets the treatment JAMES M. LEAVER. 

